The present invention relates to a fibrous insulation blanket pre-cut for custom fitting the blanket into both standard and non-standard width structural framework building cavities, such as wall cavities; and, in particular, to such a blanket that can be handled as a unit when insulating standard width cavities or easily torn apart (by hand) along the cuts to form narrower blankets when insulating less than standard width cavities.
Building structures, such as residential houses, industrial buildings, office buildings, mobile homes, prefabricated buildings and similar structures typically include walls (both interior and exterior), ceilings, floors and roofs which are insulated for both thermal and acoustical purposes, especially the exterior walls and the roofs of such structures. The walls, ceilings, floors and roofs of these structures include framing members, e.g. studs, rafters, joists, beams and similar support members, which are normally spaced-apart standard distances, and to which sheathing, paneling, lathing or similar construction materials are secured to form the walls, ceilings, floors and roofs. While the contractor seeks to maintain the spacing of such framing members in these structures at these standard distances for ease of construction and insulation of the elongated cavities formed in these walls, ceilings, floors, and roofs, frequently the walls, ceilings, floors and/or roofs of these structures include elongated cavities defined, at least in part, by adjacent framing members which are spaced apart a nonstandard distance less than the standard spacing between framing members. Studies have shown that in a typical residential house, it is common for 50% or more of the framing members in the exterior walls of these structures to be spaced apart at nonstandard distances less than the standard spacing for such framing members.
When insulating these elongated cavities of various nonstandard widths, less than a standard width, it has been the practice to take an insulation batt preformed to fit the standard cavity width and reduce the width of the insulation batt by cutting off and removing a strip of insulation material from one or both longitudinal edges of the insulation batt. U.S. Pat. No. 5,331,787; issued Jul. 26, 1994; to Kaarst; illustrates this approach. In the invention of this patent, the insulation batts or panels have widths at least equal to a predetermined maximum distance between adjacent support members defining the cavities that the batts or panels are to insulate. The batts or panels are provided with facings that are folded over along the longitudinal edges of the batts or panels so that strips of insulation material can be cut away from one or both longitudinal edges of the batts or panels to fit the batts or panels between support members spaced apart less than the predetermined maximum spacing. This method of trimming the insulation batts at the job site by cutting the batts to fit between the more closely spaced support members is time consuming, raises a significant risk or safety issue, relies heavily on the worker's skill to accurately trim the batt or panel.
U.S. Pat. No. 4,866,905; issued Sep. 19, 1989; to Bihy et al; discloses another approach to the problem. In the invention disclosed in this patent, a continuous strip of fibrous insulation with transverse marking lines is provided. The worker cuts the strip of fibrous insulation at the job site to a width somewhat greater than the spacing between the framing members, i.e. rafters, defining the space to be insulated. Of course this method of forming insulation batts or panels at the job site is also time consuming and relies heavily on the skill of the worker cutting the insulation strip to achieve a good result.
A different approach to the problem is shown in U.S. Pat. No. 2,335,968; issued Dec. 7, 1943; to Sawtell. In the invention of this patent, the lateral edges of the insulation blanket are turned down to enable the insulation batt to be placed between framing members, i.e. rafters, spaced closer together than the width of the insulation batt. This approach does not require any cutting or trimming at the job site, but it can be used only where the spacing between the framing members is slightly less than the width of insulation blanket.
Thus it can be seen that there has been a need to provide fibrous insulation blankets or batts which can be used to either insulate standard width framework cavities or be quickly and easily reduced in width to fit less than standard width cavities without a need to cut the fibrous insulation blankets at the job site with knives or similar cutting tools.